Insect cell lines

Huynh, C.Q. and Zieler, H. (1999) Construction of modular and versatile plasmid vectors for the high-level expression of single or multiple genes in insects and insect cell lines. Journal of Molecular Biology, 288 (1), 13—20. 

Human pathogens (e.g. HIV) do not generally infect insect cell lines. 

Continuous insect cell lines were first established in culture over three decades ago when Grace [45] succeed in growing cells from female Antherea eucalypti moth ovaries. Since Grace s first report on four cell lines, over 400 lines have been established from more than 100 insect species representing every economically important insect order [46,47]. 

Among the insect orders, tissues from Lepidoptera have attracted the most attention because of their historical importance as agricultural pests [48]. Insect cell lines have been established from a variety of tissues, mostly from undifferentiated ovarian or embryonic [49]. The undifferentiated nature of the embryonic tissue has made possible the establishment of continuous insect celllines from diploid tissues [49]. 

The range of carbohydrate utilisation differs between different insect cell lines. Glucose, fructose and maltose can be used individually as carbon sources in Sf9 cell cultures [42]. 

The progress of reverse chemical genetics research is influenced by the efficiency of generation of active recombinant proteins. In recent years, numerous systems for the expression of the recombinant proteins have been developed. Of these, the baculovirus system is considered to be the most efficient. Typically in the baculovirus system, an insect cell line (for example, Sf9) is used as a host for the expression of recombinant proteins. In the present report, we describe the novel application of Kaiko as a host in the baculovirus system for the expression of recombinant... 

Zhang, P-F., Klutch, M., Muller, J., Marcus-Sekura, C. J. Susceptibility of the Sf9 insect cell line to infection with adventitious viruses. Biologicals 22 205-213 (1994). 

Insect cell culture was started in 1915 but no cell line capable of replicating indefinitely was established until 1962. In that year Grace showed the ability of the insect cell line Antheraea eucalypti to replicate indefinitely in... 

High-Five cells (BTI-TN-5BI-4) are derived from Trichoplusia ni cells and are frequently employed due to their capacity to express high protein levels when compared with other insect cell lines, such as Sf-9 cells (Rhiel et al., 1997). This cell line shows high growth rates in adherent culture, and can easily be adapted to grow in suspension and in serum-free media. 

A comparison between insect and mammalian cell culture technology shows various similarities and differences. Due to the fact that insect cell lines typically derive from specific organs or non-differentiated embryonic tissues, the same cell line can proliferate in suspension or in adherent manner (in monolayer). This versatility in growth mode, which contrasts with most mammalian cell lines, increases the choices of bioreactor types and culture strategies for production. Contact inhibition shown by various mammalian cell lines is low or absent for insect cells, and they tend to aggregate in suspension or in adherent cultures. 

Rhiel M, Mitchell-Logean CM, Murhammer DW (1997), Comparison of Trichoplusia ni BTI-Tn-5Bl-4 (High Five ) and Spodoptera frugiperda Sf-9 insect cell line metabolism in suspension cultures, Biotechnol. Bioeng. 55 909-920. 

Standard temperatures are usually defined for every known cell line, for example, mammalian cell lines are usually cultured at 37°C and insect cell lines at 28°C. However, studies have demonstrated that temperature modifications can lead to changes in certain parameters, such as increased productivity of recombinant proteins or decreased byproduct generation. 

Mitsuhashi J (1982), Determination of Essential Amino Acids for Insect Cell Lines, Academic Press, New York. 

Donaldson MS, Shuler ML (1998), Low-cost serum-free medium for the BTI-Tn5Bl-4 insect cell line, Biotechnol. Prog. 14 573-579. 

Drews M, Paalme T, Vilu R (1995), The growth and nutrient utilization of the insect cell line Spodoptera frugiperda Sf9 in batch and continuous culture, J. Biotechnol. 40 187-198. 

Donaldson M, Wood HA, Kulakosky PC (1999), Glycosylation of a recombinant protein in the Tn5Bl-4 insect cell line influence of ammonia, time of harvest, temperature, and dissolved oxygen, Biotechnol. Bioeng. 63 255-262. 

Kulakosky PC, Shuler ML, Wood HA (1998), N-Glycosylation of a baculovirus-expressed recombinant glycoprotein in three insect cell lines, In Vitro Cell. Dev. Biol. 34 101-108. 

Lopez M, Tetaert D, Juliant S, Gazon M, Cerutte M, Verbert A, Delannoy P (1999), O-glycosylation potential of lepidopteran insect cell lines, Biochim. Biophys. Acta 1427 49-61. 

The establishment of insect cell line cultures allowed a detailed study of the infection cycle of many baculoviruses. These cell lines are easily cultured in vitro and their maintenance is relatively simple. The majority of the cell lines can be cultivated using a temperature of 25-30°C. However, the best temperature for the growth and infection of Sf9 cells is around 27-28°C (King and Possee, 1992). 

An important aspect of biopesticide production using insect cell lines is the maximization of cell growth. Culture media must satisfy the environmental and nutritional requirements of the cell line. Hence, many studies have been carried out to characterize the nutrient requirements and metabolic pathways of these cells (see Chapters 4 and 5). 

Insect cell lines present different susceptibilities to virus replication. A cell line is called permissive when it can support full virus replication and all stages of viral cycle are completed, leading to polyhedra production and lysis of the host cell. Semi-permissive cell lines allow partial virus replication, possibly due to a restriction at a particular viral cycle stage (Bilimoria et al., 1992). Abortive cell lines are those in which the resulting virus may have a cytopathic effect, but there are no infective particles produced (Carpenter and Bilimoria, 1983 Liu and Bilimoria, 1990). 

In vitro infection can be established routinely using infected larvae hemolymph containing viral infectious particles (BVs). These particles can be used to inoculate susceptible cells (see secondary infection, Figure 19.2). NPV replication in insect cell lines seems to be more efficient than GV replication in vitro. While many studies have demonstrated the susceptibility of NPVs to different cell lines, few efficient replication systems have been obtained for GVs (Miltenburger et al., 1984 Winstanley and Crook, 1993). 

Lynn DE (2003a), Comparative susceptibilities of insect cell lines to infection by the occlusion-body derived phenotype of baculoviruses, J. Invertebr. Pathol. 83 215-222. 

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